Having completed an extraordinary body of silent films in 1929, Fritz Lang entered the sound era with this bold masterwork, an expressionist thriller that captured the ugly mood of Germany just before the Nazis came to power, and was banned as soon as they took over.

M provided the blueprint for police procedural thrillers, anticipated the vogue for stories about serial killers, and centres on a great performance by Peter Lorre as a child murderer who creates panic in a German city and unites the authorities and the underworld in hunting him down. This subtly lit film uses sound in innovative ways, and concludes with a deeply moving scene in which Lorre's Hans Beckert is tried in a kangaroo court convened by criminal bosses, one of them played by the great actor Gustaf Gründgens – inspiration for the novel (by Klaus Mann) and film Mephisto.

This two-disc set (PG, Eureka) contains a carefully restored print of M, commentaries, an interview with Lang (by Peter Bogdanovich), a documentary and the special bonus of the recently rediscovered British dubbed version in which we hear Lorre perform in English for the first time.